Ethereum's Glamsterdam Upgrade Aims to Make Block Builders Compete for Their Lunch 💺

Ethereum developers are preparing "Glamsterdam," a forthcoming network upgrade framed around ePBS (Enshrined Proposer-Builder Separation) and FOCIL (Fork-Choice Inclusion Lists), with the next major milestone being the Glamsterdam spec freeze, targeted for April 2026. Developers have framed the work as a follow-up to the previous Fusaka upgrade, which was scoped in late 2025 and included the shift to 6-second slots and the inclusion of EOF (Ethereum Object Format) features.

The pitch for Glamsterdam centers on shifting a key piece of block construction off the validator path. Under ePBS, validators would no longer directly assemble block bodies; dedicated block builders would handle execution payloads, with the protocol enforcing proposer-builder separation rather than relying on external relays. FOCIL adds a second piece: a small set of attesters would be selected to publish inclusion lists each slot, guaranteeing that transactions meeting minimum criteria make it into blocks. The $ETH price was $1,966.62 at the time of publication, according to CryptoNews.

Proponents argue the architecture could improve censorship resistance, raise validator rewards, and reduce the surface area for MEV extraction by removing the need for trusted relays. Critics counter that enshrining these roles adds protocol complexity and may lower validator profitability in some scenarios, since today's MEV-related rewards accrue to validators. Glamsterdam also follows EF staff reductions announced in early 2025 and arrives as Ethereum continues to track competing networks on throughput metrics.

Combined with broader 2026 narratives around stablecoin settlement on Ethereum and expanding Layer-2 rollup usage, Glamsterdam is being positioned as the network's next structural overhaul. As one developer summarized on a recent All Core Developers call, the goal is to ensure "builders get paid for what they actually built," reflecting the broader design ethos of pricing block construction explicitly at the protocol level.